Hydrangea arborescens 'Annabelle' won't exceed 4' height, but it does sucker and if not managed will increase in width. There are several reblooming (remontant) Hydrangea macrophylla that even if they are hit by spring frosts will bloom well over the summer. All are happiest with afternoon shade.

Rhododendron 'Checkmate' (a short version of the PJMs), R. 'Yaku Prince', as well as some others if you have acid soil. I also have a Leucathoe which has never exceeded 4' without pruning, and L. 'Rainbow' while listed as 3'-5' is slow enough growing so that it can probably easily be kept below 4'. It has quite ornamental leaves, but also likes acid soil. Both the Rhododendrons and the Leucathoe are evergreen.

Several of the small Deutzias, such as 'Chardonnay Pearls', 'Nikko', 'Yuki Snowflake' will bloom well with half shade (mine get afternoon shade.) In my garden they top out at about 3 1/2 feet.

One of my favorites, a semi-evergreen plant with white-edged leaves and a long, though never stunning, bloom time, is Daphne x transatlantic 'Summer Ice'. It is often both the first and last blooming shrub in my garden. Scented, and I have found it to not fit the reputation of fussiness that many Daphnes have.

Oooooh, they all sound luscious. I will check them out nhbabs!
I have sun between noon and about 4-5...west side of house that has an overhang and mature trees to the west that shade starting early evening. So the sun is strong and hot, but doesn't qualify for full sun. I'll look them all up and see what might work best. I like the idea of the daphne, since it is right next to my patio area. Thanks for the suggestions!

A favorite would be a dwarf form of Fothergilla, as they have interesting flowers, and can have the most magnificent red color for Fall. Even with shade they can be orange or gold.
Several dwarf forms of Hydrangia quercifolia are available, and they have flowers that last and last, while slowly going from white to pink to paper-bag tan, for Winter. Fall foliage can be mahogany and wine.

With 4-5 hours of western sun, you can probably get away with many sun plants as it will be bright shade for additional time.

H. Annabelle and H. macrophylla won't be happy with afternoon sun - will wilt every afternoon.

I love Fothergilla and have several, but probably wouldn't plant it by a patio where I'd be often in summer. Mine are planted by a patio I use spring and fall only (too hot in the summer) where I can enjoy the spring flowers and fall color, but don't have to look at the post flower panicles which I find unappealing.

Fothergilla in July looks like the shrubs in the lower left and upper right of the photo.

bella, i call your area 'full sun' as evening shade doesn't count, imo. Boy do you have a million options. Don't you want to get a shrubs book w/ good photos from your library? or go to a botanical garden where you can get many many ideas?

my rule of thumb is that when choosing plants for an important, key, location, I want them to give me at LEAST 2 seasons of interest, and preferably more. And i like to mix foliage interest w/ flower interest w/ stem and/or berry interest.
You only need ONE shrub? What are the other shrubs around it? Variegated or not? If I were picking only one, I would pick a small variegated weigela. Fantastic green and yellow foliage, flowers forever. Boy do i love daphnes but for me they are far from the easiest to grow. Chardonnay pearls deutzia is very dainty and keeps its yellow foliage in the shade, so why waste it in full sun(besides, it will bleach out, i think, w/ hot sun.) A small red twig or yellow twig dogwood bush will give you foliage and stem interest but fyi, their flowers are timid.
babs, do you grow Blue Shadow fothergilla? To DIE for!

p.s. this abelia is sold by broken arrow nursery and looks perfect for your spot.

if you look further on the linked site, they list 'small shrubs' where you could do a fast preview of them.

Here is a link that might be useful: abelia

Thank you all for the suggestions. I will look into fothergilla...the variegated weigela also sounds very interesting, because I don't have anything variegated in this area at all.

Yes, I only need one...I took down an Alberta spruce and put in one more Little Lime hydrangea at the edge of a group, leaving space for one more shrub, directly next to the patio area.

Mindy, my Fothergillas are all 'Mt. Airy'.

Another option would be one of the shorter clematis on a relatively low support which it could climb and then spill down.